Where To? The Dream Space Missions of 3 Scientists

NASA now faces a 20 percent cut to its planetary science budget in 2013, but that hasn't stopped researchers from dreaming of faraway places. Popular Mechanics asks three planetary scientists about their ideal space-exploration plans.

Where To? The Dream Space Missions of 3 Scientists

Where To? The Dream Space Missions of 3 Scientists

Less than two weeks from now, the Mars Science Laboratory will reach the Red Planet. After scientists hold their breath through the sophisticated but terrifying landing procedure, the car-size Curiosity rover should be in position to explore new regions of our neighboring world.

Curiosity may well capture the imagination of the world, just as the Mars Phoenix Lander did when it found evidence of water ice back in 2008. Nevertheless, the future of U.S. planetary science remains in limbo. As part of ongoing belt-tightening in Washington, President Barack Obama proposed to cut $309 million from NASA planetary science, or about 20 percent of its $1.5 billion budget.

"American taxpayers have always gotten a lot of bang for their buck from planetary science, so this proposed action by the administration is, frankly, puzzling," says Mark Sykes, director of the Planetary Science Institute in Tucson, Ariz., and member of the Dawn mission now surveying the asteroid belt. However, Congress would have to approve the cuts, and "there's an awful lot of support among lawmakers for restoring the budget," he says, "so that's uplifting."

Budget worries are business as usual for publicly funded scientists. Yet, even as the money for future missions is on the chopping block, the array of targets in the solar system has become all the more enticing. Besides the MSL Curiosity rover approaching Mars, there's news on a seemingly weekly basis about frozen lakes on Saturn's moon Titan or a subsurface ocean on Jupiter's moon Europa.

Some countries are prepping to go to these faraway places. China is vastly ramping up its space program; the European Space Agency just approved a probe for Jupiter's icy moons. NASA certainly wants to. About every 10 years, the agency organizes a panel of planetary scientists to boil down hopes and dreams into a budget- and timeline-conscious report called a decadal survey. The latest version, Visions and Voyages for Planetary Science, was published last year.

In the same spirit, we interviewed three top planetary scientists about their dream missions—without budgetary, timeline or bureaucratic constraints. So, where to?

Titan

Titan

The Cassini-Huygens mission has explored Saturn and its system of moons since 2004. Shortly after arriving there, the main spacecraft dropped the Huygens probe to the surface of Titan, Saturn's largest moon. It landed in mud rich with ethane, methane, and other organic molecules. All these molecules exist in a transient state between liquid and gas because of a surface temperature of minus 290 degrees Fahrenheit.

Planetary scientist Bonnie Buratti still works on the Cassini program; the orbiter still sends back new information about Saturn and its moons daily. But, she says, Titan is so remarkable that it deserves a new look with even better equipment.

"One scientist back in the Voyager era, I think in the 1980s, called Titan ‘the Earth in deep freeze,' " Buratti says. "Since we landed Huygens on the surface, we've found lakes of liquid ethane or methane, we've seen clouds and rain, we've seen channels where the liquid has pooled and flown. . . It's very Earth-like."

Titan may also harbor a liquid-water ocean beneath its mushy crust, and volcanoes that spew the material upward. Mixed with the organic molecules, life may not be an absurd notion. "All of life's building blocks seem to be on Titan. Who knows? Maybe simple bacteria are living under the surface," she says.

Buratti says that if money were no object, she'd send a trio of spacecraft: a wheeled rover to poke around the lakeshores, a balloon to sample the atmosphere as the dirigible rises and falls, and an orbiter to study weather and erosion on the megamoon from high above. Her rover would have a digger to look under the cold muck, a microscope to analyze samples, a mass spectrometer to sniff chemicals, and more.

"We could learn a lot about the same processes on Earth by going to Titan," she says. "It's a wonderful place for comparison."

Outlook: Very possible.

Over the past two years, NASA looked at 28 candidates to be the next Discovery mission, a $425 million planetary science mission, and narrowed the competition to three: a Mars Phoenix–like lander, a comet-hopping robot, and a boat for Titan's lakes. So far, most planetary scientists seem to be rooting for the boat, called the Titan Mare Explorer, or TiME. If NASA selects TiME later this year, the boat would be scheduled to land in 2023. And if it makes some tantalizing discoveries, the U.S. could invest more in the exploration of Titan—perhaps in Buratti's rover, balloons and orbiter.